Pope Benedict XVI has changed the rules that will decide his successor after his death, returning to a traditional method requiring a two-thirds majority.

Pope John Paul II had altered the voting process to allow a candidate to be elected with only a slight majority.

His reforms were intended to speed up the voting process and to avoid a deadlock when electing a new pope.

But spokesman said a return to the old system "would guarantee the widest possible consensus" for a new pope.

From now on, a candidate will need two-thirds of the votes of cardinals taking part in the conclave regardless of how many times the ballot needs to be repeated.

Pope John Paul had introduced the reforms to avoid deadlocks like that which occurred during a 13th Century conclave when negotiations dragged on for three years.

Pope Benedict, 80, has made an attempt to address this issue by calling for a run-off vote between the top two candidates if the voting goes as far as 33 rounds.

Critics of Pope John Paul's system said that instead of simply avoiding a deadlock, the changes he made in 1996 could in theory empower any majority willing to hold out until the two-thirds requirement expired.

Pope Benedict - the former Cardinal Joseph Ratzinger - was elected to lead the Roman Catholic Church in one of the fastest conclaves in history.

Cardinals who take part in the process take a vow of "absolute and perpetual secrecy".

The voting took just two days in April 2005 and he was reported to have received 84 of the 115 votes after four rounds of voting.